DFALOHAGO should get you 15% off a ticket to The Aloha State while
DFDECMXCRPL should do for the latter bloc.
As usual, there are oddly juxtaposed terms and conditions that I could spend the next half hour breaking down and laying out for you, so I’ll give you the quick summary. You need to travel to Hawaii between December and March 6, in contrast to travel between now and December 20 for Mexico and the Caribbean. You also need to book pretty soon. If you want the full terms and conditions, check the AA website.
Be sure to bounce over to the airfarewatchblog as well; they have a team of staff and writers working full time finding us these codes and fares.